Because the HIV pandemic undergoes continual change in its locations and affected populations, it is crucial to study the risk behaviors of mobile and migrant populations. It is increasingly important to recognize and study the attitudes and behaviors which determine risk as they are transported across borders, changing as people adapt to new environments. While the proposed research will be carried out in New York City and nearby counties, the lessons learned have implications for policy and prevention planning for other areas of the country and for international research on HIV and mobile populations. This study proposes both qualitative and quantitative research methods to identify and describe new Hispanic migrant and immigrant populations and their HIV risk in the Metropolitan New York Area, one of the most affected in the nation by HIV/AIDS and immigration. Neither accurate population estimates nor reliable seroprevalence data exist for these increasing and largely hidden and hiding populations who fear deportation, stigma and a system with which they cannot communicate. The research will be conducted in urban, sub-urban and rural locations, and compare not only the cultural factors which influence risk of HIV and STIs, but also the environmental factors which provide the context for both risk and prevention. The research will focus upon recently arrived Mexican, Central American (Salvador, Honduras and Guatemala) and Dominican communities in these three types of locations. The study will be conducted in three phases: Year 1 will be dedicated to ethnographic exploration, identifying and describing the communities and their HIV risk. Year 2 will build upon the results from Year 1 and will implement a survey with 640 individuals in the target populations. Year 3 will be dedicated to completing the survey, data analysis, and the dissemination of results.